1. Field of the Invention
This invention relates to a weft straightener attached to various machines which are used for dyeing, printing and finishing of natural and synthetic fiber cloths. Particularly, this invention relates to a pin wheel type weft straightener which is attached to various machines for use in dyeing, printing and finishing of natural and synthetic fiber cloths and which straightens the skewing or the bowing of a travelling cloth.
2. Description of the Prior Art
As a weft straightener using pin wheels, the weft straightener disclosed in Japanese Utility Model Publication No. 015056/1980 has been already known. In this straightener, a pair of pin wheels are provided along both selvages divergently and in a weft direction, and a group of pins are projectingly implanted in the outer peripheral parts of these pin wheels. The skewing or the bowing of the cloth is straightened by subsequent pinning of both selvages of the cloth and by the difference of rotation speed of both pin wheels, namely by the difference in the rate of over feed of the cloth.
In Japanese Utility Model Publication No. 004700/1983, an improved weft straightener is disclosed. In this straightener are provided a pair of pin wheels for pinning both selvages of a travelling cloth with a group of pins projectingly implanted on the outher peripheral parts of the pin wheels; a pair of pin wheel stands which support the pin wheels inclinably in relation to the tangent or the neighborhood of the pinning starting position, and which are movable in the weft direction; an inclination controlling means which adjusts the inclination angle of each pin wheel to a desired divergent angle; and position controlling means which adjust each pin wheel stand to a desired position.
In this improved weft straightener, control of an inclination controlling means which adjusts the inclination angle of each pin wheel to a desired divergent angle; and position controlling means which adjust each pin wheel stand to a desired position.
In this improved weft straightener, control of an inclination angle keeps the rockable central axial line straight, and scarcely changes the pinning starting position on the outer peripheral part of the pin wheels, which dispenses with the needs for adjustment of cloth racking when the inclination angle of each pin wheel is adjusted, or adjustment of the location of a brush roll or other attachments. In addition, this type of straightener, wherein each pin wheel stand is locked to each feed screw shaft, and which is disposed across the weft independently of other pin wheel stands, and in which each pin wheel is moved to a desired position in the weft direction by a forward or backward turn of the feed screw shafts, enables, to a certain degree, the control of the intervals between both pin wheels in accordance with the width of a cloth, and also enables automatic follow up of the pin wheels to the selvages of a running cloth.
However, the convention pin wheel type weft straighteners, including the one disclosed in Japanese Utility Model Publication No. 04700/1983, had the problem that they induced deformation or rupture of a travelling cloth under abnormal tension in the weft direction while being pinned by each pin wheel.
Furthermore, in the conventional weft straightener, when movement of the travelling cloth on the pin wheels is stopped while the cloth is being pinned, the cloth on the pin wheels is stretched. If the intervening period is prolonged, deformation or rupture of the cloth is unavoidable, which leads to deterioration in quality and the production of inferior articles.